<!DOCTYPE html>
<html>
<head>
  <style>
    .container {
      position: relative;
      width: 500px;
      height: 300px;
      background-color: lightgray;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    
    .box {
      position: absolute;
      width: 200px;
      height: 200px;
      background-color: coral;
      display: flex;
      justify-content: center;
      align-items: center;
      color: white;
      border-radius: 10px;
      border-color: antiquewhite;
      border-width: 2px;
      border-style: double;
    }
    
    .text {
      text-align: center;
      font-size: 24px;
      font-weight: bold;
      text-transform: uppercase;
    }
  </style>
</head>
<body>
  <div class="container">
    <div class="box">
      <p class="text">Hello, CSS!</p>
    </div>
  </div>
</body>
</html>